Method of operating heating furnaces



Y, 16,55 Jan' u 1927 T. J. COSTELLO Re 2 ME'IIHOD OF QPERATING HEATING FURNACES Cri Final Filed Oat. 5 0! 1.929 2 Sheets-Sheet@ 1 1V l Re, 16527 l 927 T. J. COSTELLO 'METHOD OF OPERATING HEATING FURNCES Original Filed Oct. 30, 1920 2 Sheets-Shea? :2

Reissued Jari. ll, 1927.

UNITED STATES PATENT OFFICE.

THOMAS a. COSTELLO, or WARREN, OHIO, AssrsNoR. BY MEsNE'AssIGNMENTs. To COSTELLO ENGINEERING COMPANY, or PITTSBURGH, PENNSYLVANIA, A coa- PORATION OE PENNSYLVANIA.

METHOD 0E OPERATING vI-IIEA'I'INCr FURNACES.

Original application led October 30. 1920. Serial No. 420.593. Patent No'. 1.447.588. Divided and appli. cation ledllay 28, 1921, Serial No. 473.436, Patent No. 1.530.239. dated March 17, 1925. Application for reissue tiled June 25, 1926,

Figure `l is a longitudinal section illustrating one form of furnace for carrying out my invention.;

Figure 2 isla detail view, partly 1n end elevation and partly in seet'ion, showing the positioning of the billets; and

Figure 3 is a sectional plan view, also showing the positioning of the billets 1n the furnace. Y

My invention has relation to the method of operating heating furnaces, and more particularly to the operation of furnaces for heating sheet and tin plate bars, slabs or billet-S.

One Object of the present invention 1s to utilize the lnaterial being heated as a division wall between adjacent heat circulatingr flues, whereby the opposite sides of the material are directly subjected toY theaction of the heated products of combustion passing through said fines.

A further object of the .invention is to utilize the projections formed on the vmaterial during shearing as a separating or spacing means for adjacent billets, bars or Slabs.

A still further object 1s to provide for positioning the bars, billets or slabs in the furnace in such a manner that they are prevented from toppling over and the passage of heat between adjacent bars, billets or slabs is facilitated.

The present application -is a division ofy my application, Serial No. 420,593, Patent No.'1.447,588, granted March 6, 1923. l

It has heretofore been proposed to heat metal billets by feeding.r them one behind -tbo other into a' furnace to form a division u'all between adjacent flues and passing the heating medium in the same direction through the. flues above and below the' billets. Such furnaces are generally known as the split llame" type.

ly the present inwnliou the heating uicdiumis passed over one side of the bil- 'lels in onedircetion and then over ythe other side of the billets in the Opposite direction. Furthermore, the billets are preferably spaced to permit the passage of a portion of the heating medium between adjacent billets.

This method of heating is of great advantage as compared with the split dame Serial No. 1 18,576.

method. In actual practice it is impossible to make halt of the flame flow above the stoel and the Otherhalf below-One of the two passages will always be favored. This generally results in non-uniform heat distribution in the billets; a condition which is fatal to accurate .rolling or other operations succeeding the heating. To overcome this a soaking,r hearth has generally been resorted to. 'lhat is, the: furnace has been iliade longer than necessary in an attempt to give the billet time to equalize its heat content by conduction.

In the present invention, the heating, medium is passed along one side of the billets in one direction and then it is reversed and passed along the other side in the other direction. The surface which first comes in contact with'the heating medium will get hotter than the material last touched there- .by since there is necessarily a temperature ggadient'along the path of the heating mc-` di'lim. Therefore, when a billet first enters the furnace it will be heated more on one side than On the other. Thisis Offset to some extent,` however, by the spacing of the billets. The pressure `drop through the furnace induces the passage of the heating medium between the -billets thereby heat-ing them on all sides and tending to equalize the heat content of a billet by conduction more rapidly than would be the case if the bil-let were heated on two sides onl It will be noted that the heating medium reverses itself at the delivery end of the lfurnace so that as the billets travel through the furnace the gases above and below them approach the same temperature and thebillets when delivered are uniformly heated. The reversal of fiow of all the heating medium does away with the non-uniformity of heating found in the split flame type of furnace and also eliminates the large hearth formerly necessary. that a soaking hearth may be used to insure the heating of the core of large billets but it need not be so large as has heretoforebeen necessary.

It willv be understood Referring to the accompanying drawings in which I have shown a preferred method of carrying out, my invention, the numeral 2 designates the heating chamber of a pairheating furnace of the continuous type.

in a reverse direction, this flue or ilues coni-` municating at the vdelivery end of the furnace with the heating chamber above the slideway through a suitable opening or openings 6. A particular furnace which I' prefer to employ is more fully shown and described in luy said application Serial No. 420,593, Patent No. 1,447,588.

7 designates any suitable pusher device for pushing the bars, billets or slabs A to be heated, into und through the heating .diately thereafter,

chamber 2, this pusher being formed with a slopingr face Sfor maintaining the bars, etc., in an inclined position, as'shown. `9 designates any suitable doorwand 1() any suitable actuating mechanism therefor,- this door closing the entrance opening 11 into the heating chamber. 12 designatesa re-l taining device, which Vis shown as being in the forni of a hooked ariln pivoted at 13 and adapted to fallby gravity into engagement with the outermost bar or slab and heid the it by the same at the inclination given l pusher 7. The lower face of this hooked arm is beveled so that as the bars or slabs are pushed thereunder by action of the pusher',v the arm will readily niove upwardly and permit the passage thereof. .Immethe arm will drop down-J wardly to catch the last bar or slab inthe manner clearly shown in :Figures 1 -and 2, thus maintaining the entire series thereof in inclined positions. The bars or slabs bc ing set on edge in this 1nanne rtheir inclination prevents the leading bars or slabs from toppling over, and insures their passage throughthe furnaces in such inclined positions.

It will also be noted that the liuc or flucs 5 lare open atthe top, the bars or Abillets forming in eflcct the top wall of such flue .or fines, and a division wall between the said flue. or fines and the heating space above the bars or billets. In this manner the heated products of combustion are first caused to pass longitudinally above thebars or ybillet-s and thence backwardly in contact with the lower edges of the same, thus giving, a very eli'ective and uniform heating action, as well as utilizing considerable heat' which would otherwise be passed to the stack and be lost. .Y

By reference tolFigures 2 and 3, it will surfaces of the material is prevented, and

that due to the more intimate contact with the, heated products of combustion, the period necessary for tion and uniform heating may be considerably reduced. The passage .of the products proper heat penetraof combustion directly between the adjacent 'bars or slabs is facilitated by the use of the open top due or iues 5, so that'tlie material itself forms the division Wall between oppositevly moving currents, of the heating medium.

In operation, heating gases enter the 'fun nace through the opening 4 andI move toward the right, as viewed in Figure 1 above the billets and as indicated by arrows. As they move in this direction a certain .portion of the gases passes between the billets on account of the openings provided by the burls thereon, while the remainder of the heating gases travel to the right furnace, then downwardly and to the left underneath the billets. find their way between the billets also pass into this flue 5 from which all the gases travel to the stack, as indicated by the dotted arrow; The heated billets are removed in any convenient manne-r at the right hand end of the furnace, the leading billet of the advancing line being'preferably removed land the remaining line .moved forward.

lVhile I have illustrated one manner of cariving out my invention it Will'be` underw stood that' I am not limited to the forni shown as the invention may be otherwise einbodicd within the scope of the following clauns. l

I clarin: l l. The method of heating billets, coinprising r'charging the'billets into a heating furnace, and supporting said billets from the'charging end of the furnace to maintain thein similarly inclined .within the furnace, and to prevent toppling thereof, substantially as described. 1 2. The method of heat-ingsheet'bars, coniprising feeding the sheet bars broad side into a heating' furnace, maintaining the sheet bars within the furnace' so disposed with respect to the horizontal that the sheetbars, unless supported would topple, and supporting the sheet Vbars against toppling. 3. The method ofheating sheet bars', cornprising feeding the sheet bars inclined to the horizontaly into a heating furnace, main# hand end of the The gases which i furnace, substantiall taining the sheet bars within the furnace and substantiallyY similarly inclined transi rcistly ot'thc furnace, and supporting the sheet barsl against topplingdui'ing their i bioad'side'travel through the furnace.

4.' 'lhe method of heating billets, comprising feeding said billets into a heating furnace, causing .said billets to form a d1vision wall l,-et\\'ecn adjacenttlues, and passing a heating medium through said flues, said illets 'being held in spaced relation by the burrs formed thereon during shearing, substantially as described.

5. The method of heating'billets, comprising `feeding said billets into a heating `furnace while maintaining them in an inclined position, causing said billets to form adivision wallrbetween adjacent flues, andk assin aheating medium through said ues, substantially as described. v

6. The method of heating billets, comprising `feeding said billets into a heating furlnace,vcausing said billets to form a division wall between adjacent fines, and passing a heating. medium in succession first through one of said flues in one direction on one side of thel billets, -for substantially the entire length of the charge of billets in the furnace,l then to theo posite sideof said billets to anothei'vof sai fflues, and then through said .lnstinentioned flue in a direction opposite to the directionof travel through the first mentioned flue, for substantially the entire length ofthe charge of billets in the as described.

7. The method of eating billets, comprising feeding said billets into a heatin furnace, causing said billets to formv a division wall'bctween' adjacent flues, and passing a heating iiiediuin in succession first throu h one. of said Hues in one ,direction on one si e of the-billets, thentp ,the opposite side of said billetls toanoth'er of said flues, and then through said lastnientionedflue in a direction 4ogposite to the.'l direction of ytravel throug the first mentioned flue, the heating ymedium being introduced to and taken from ,the lfluesad'acent the same end of the furnace for su tantially'the entire le h of the charge of billets in the furnace, su tantially as described.

8.L Themetliod of heating billets, comprising .feeding said billets into a' heatin furnace, causing said billets to forni a div'mion wallbetwcen. adjacent dues, and introducing a heating medium into said furnace and causing it to initially travelthroug'h one of said flues in the direction of travel of the billets through the furnace, the heating mediunibeing introduced. to and taken from the flues adjacent the saine end of the furnace, substantially s described.

9. The method of heating billets, comprising feeding said billets into a heating furnace, causing said billets to. form a division wall between adjacent lues, introducing a heating medium into said furnace, causing said medium, to initiallytravel through. one. of said ilues in the direction of the itravel of the billets through the furnace, and then causing said medium to pass to the op )osite side of said billets and travel throng another of said tlues in a direction op osite to its direction of travel' through sai first mentioned flue, the heating medium being introduced to and taken from the fluesadjacent the same end of thel furnace, substanp tially as described.

10. The method'of heating billets which includes feedin billets into a heating furnace, passing adieating medium throu h the furnace over one side of the billets, an then changing its direction and passing it back through the furnace over the other side/of the billets, meanwhile allowing ,a portion of the heating medium to ass between the billetsand removing the illets from thejurnace adjacent the end where the direction vfof travel of the heating medium is changed, the heating medium bein ,introduced to and taken from the fines a jacent the other ebd of the fui-nace, substantiallyas described- 11. The method of heating billets which includes feeding billets in a row into a heating `furnace, passing a heating medium through the furnace over one side of the bilpassing it aroundthe `foremost billet.

=nos

12. The method-cf heating billets whichincludes feeding bllets'in a row into a ,heating furnace, passing a heating medium through the furnace over one side .o f the,billets, passing it around the foremost-.billet and back bver the other side of the billets, removing the foremost billet and advancing the remaining billets bjinserting a cold billet at the other end of I the row, the heating medium being introduced to and taken Afrom the flues adjacent the end of the furnace where the cold billets are introduced, substantiiilly as described.

13. The method of heating hi bich includes passing a 'heatim-,l intalimi iirst over oneside of :i rowot' billets in one dijiio ll l

rectioii and then over the opposite side of thc i billets and in the opposite direction, meanwhile allowing a portion of the heating niediuni to pass between the billets, substantially as described.

14. The method of heating billets which includes passing a heating medium in a direct manner iirst over 'one side of a row of spaced billets in one direction and'then over the opposite side of the billets and in the opposite direction, substantially as described.

1'5. The method of heating billets which includes supplying a gaseous heating mediuni to one side of a row of spaced billets, passing portions of the inediuin between different bil-lets of the ro'w at different points along the length of the row, the gases being first passed along the side of the row where the gases enter a sufficient distance to reach the points where the various portions pass between the billets and then in a reverse direction along the side of the billets o posite the side Afirst in contact with -the eating medium. substantially fas described.

1G. The method of heating billets which includes supplying a heatinginediuin to one side of a row of spaced billets, passing portions of the medium between diiferent billets of the rou at different points along the length of the row, the gases being first paed along theside of'the row Where the gases enter a suicient distance to reach the points f where the various portions pass between the billets and then in a reverse direction along tlreside of the billets opposite the side first in contact with the heating medium and providing an excess of heating medium above the quantity passing between the billets, said excess' passing over that side of the row first in contact with the heating inediuni, reversing its direction at the end of the row of billets and passing through the opposite side, substantially as described.

17. The method of, heating billets, coinprising feeding the billets into a heating furnace, and maintaining Va plurality of said billetsy inclined in the saine direction and supported substantially along one corner only' thereof bv the furnace and in a coni- .n10n plane v within the furnace, substantially as described. y

18. The ,method of heating billets, oomprising feeding the billets broad side into a eating furnace, maintaining a plurality of said billets within and transversely of the` furnace vand inclined in the saine direction therein with the center of gravity of the billets so y,disposed that a side support therefor is required tol-prevent toppling thereof, and providing a side support for the billets, substantialhv as described. v

19".- The method of heating sheet bars. com prisilig supporting the bai-son edge with the edges in a common plane` and the bars in adjacent relationshipand in an inclined position, feeding the bars broad side while so l described.

inclined and so supported into a heating furnace` andinaintaining the bars in inclined position within said furnace, substantially as 20. The lmethod of heating bars, C 'ompri'sing placing the hars in side by side inclined relationship outside of the furnace and extending transversely thereof, feeding the bars broad side into a. furnace While so inclined, and maintaining the bars in inclined position within the furnace, substantially asidescribcd. v

21..The method of charging sheet bars, comprising feeding the bars broad side while supported on edge through a charging opening and into a heating furnace. and engaging the r arinost bar of each charge at a point adjacent the charging opening of the furnace to prevent toppling.

22. A method of heating bars, comprising feeding the bars broad side into a furnace with the lower' edges of adjacent bars resting on a common support in substantially a coiniiion plane, and maintaining a lurality of the bars inclined relatively to said) support in said furnace, substantially as described.

23. In the method of heating relatively thin metal shapes. the steps comprising charging broad sider a plurality of such shapes supported edgeu'ise into a furnace, maintaining at least a plurality of such shapes within the furnace backwardly in.- clined to the horizontal and toward the charging-opening sufficiently to dispose the center of gra vityof each of such billets in a position to cause rearward toppling thereof` and supporting the billets against rearward toppling. substantially as described.

'24. In the method of heating relatively thin inetalshapes, the steps comprising charging a row Qt' such shapes broad side into furnace, maintaining at least the major part of the shapes in such row Within'the furnace backwardly inclined to the horizontal and toward the charging opening sufliciontly to prevent forward toppling ofsuch portion, charging fresh shapes into supporting relation tothosc within the furnace, and engaging said freshly charged shapes adjacent the charging cndof the furnace to prevent rearward toppling, substantially'as described.

25. In the method of heating relatively ,thin metal shapes, the steps comprising charging a row of suchshapes broad side into a furnace, maintaining at least the majo;` part of the shapes in such row within the furnace backwardly inclined to the horizontal and toward the charging opening sufficiently to preventforward toppling of such portion. and charging fresh similarly inclined shapes into supporting relation to those within the furnace., substantially as described. l v v 26. In the method of. heating relatively thin metal shapes, the steps comprising charging a. row of such shapes supported ino cornerwise into a furnace', and maintainingv the shapes of the major part of said row inclined suiicient-lyto the horizont-al and hackwardly toward the charging opening to prevent forward toppling thereof.

2". In the method of heating relatively 5 thin metal sections, the steps comprising charging a row of such sections supported edgewise into a furnace, and maintaining the shapes of the major part of said row hack'- wardly inclined to the horizontal. and toward the chargingopening .sutlicicntly to prevent forward toppling hy supporting' the r1.- w from the charging end of the furnace.

28. ln the method of heatingjrelzttirely thin metal shapes, the steps comprising charging :i row of such shapes into a fur-- nace. and supportingl the shapes' troni the churging' end of the furnace so as` to maintain the shapes of the major part of the rowhncku'urdly inclined tothe lhorizontal .sutiice'ntly to preventy forward toppling' thereof. i y

29j: The method of charging sheet hars, comprisingfeeding the hars hroad side while supported on edge into and through a heating furnace to provide a suhstantially continuous row of sheet hars within said fur nace, and engaging an end har of the row to `prevent toppling thereof.

30. In the method of heatingwelatively thin metal sections, the steps comprising charging the sections into a furnace, and supporting the same from the charging end 0f the urnace in such manner to pre- .'15 rent toppling thereof, charging fresh sec,-

tionsfinto the furnace to advance and support the previously charged sections, and similarly supporting the freshly charged sections from the charging end of the furnace, substantially as described.

31. In the method of heating relatively thin metal shapes, the steps comprising charging a row of shapes into the furnacni supporting the freshly charged sha'ies from the charging end of the furnace haclnvardly inclined to the horizontal, and utilizing the charged shapes to maintain the shapes of the. greaterV part. of the row similarly in clined, substantially as described.

32. Ingthe method of. heating relatively thin metal shapes, the steps emnprising mow ing shapes supported broad side to broad side along skids, and so maintaining the same en the skidslhat they are prevented hy gravily from forward toppling hy inaintaininw the center of gravity of such shapes in suc position as ro etfect rearward toppling, and holdingiusuch shapes .against` rearward toppling sub tantially as described.

33. In`tli`e method of heating relatively thin metal- `shapes, the steps comprising charging a plurality of .such shapes into a furnace with one of their broad faces to-' ward the charging opening of the furnace., maintaining at leasta plurality of such shapes withir the furnace vinclined to the horizontaal sutliciently to diapose the center of gravity of such shapes offset, with respect to the supporting edge thereof .sutiiciently to produce toppling` supporting the shapes againsty such toppling, and charging fresh shapes into the furnace and into engagement with the previously charged shapes.y

ln testimony whereof I have hereunto setmy hand.

THOMAS J. CSTELLO. 

